Thanks to all for the help. Dougy your circuit works great. I still need a bit of tweaking of the RC to get the timing right.
I notice the circuit must remain off for at least 4 time constants or the timing is inaccurate because of the discharge rate. Is there a way I can discharge the caps instantly or at least within a couple of seconds when the switch is turned off?
I notice the circuit must remain off for at least 4 time constants or the timing is inaccurate because of the discharge rate. Is there a way I can discharge the caps instantly or at least within a couple of seconds when the switch is turned off?